When I was getting started using Quicksilver I was always hearing about all the great things it would do, but it was a struggle to get it set up the right way to get at that functionality. In order to prevent that struggle for others I am including my basic set up.
There are a lot of plugins, and they are not all on by default. I have heard reports that enabling everything can lead to some flaky behavior. Here are the plugins that I have enabled. I have found my set up to be stable.
For the Application Preferences I have it set up thusly:
For the Extras Preferences I have this:
iTunes is configured like this:
And finally, my Handlers Preferences are set up like this: